#include <iostream>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>	// require sort next_permutation count __gcd reverse etc.
#include <cstdlib>	// require abs exit atof atoi 
#include <cstdio>		// require scanf printf
#include <functional>
#include <numeric>	// require accumulate
#include <cmath>		// require fabs
#include <climits>
#include <limits>
#include <cfloat>
#include <iomanip>	// require setw
#include <sstream>	// require stringstream 
#include <cstring>	// require memset
#include <cctype>		// require tolower, toupper
#include <fstream>	// require freopen
#include <ctime>		// require srand
#define rep(i,n) for(int i=0;i<(n);i++)
#define ALL(A) A.begin(), A.end()

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

ll s2ll (string s ){
	stringstream ss (s );
	ll res;
	ss >> res;

	return res;
}

int main()
{
	ios_base::sync_with_stdio(0);
	string N; cin >> N;

	int n = N.length();
	ll res = s2ll (N );
	rep (i, n ){
		for (int j = i+1; j < n; j++ ){
			string curr = N;
			swap (curr[i], curr[j] );
//			cerr << "curr: " << curr << endl;
 			res = max (res, s2ll (curr ) );
		} // end for
	} // end rep

	cout << res << endl;

	return 0;
}